HttpListener{
  this.port=port;
}
start{
  io.netty.channel.socket.nio.NioServerSocketChannelFactory.<init>
  io.netty.bootstrap.ServerBootstrap.<init>
  io.netty.bootstrap.ServerBootstrap.setPipelineFactory
  io.netty.bootstrap.ServerBootstrap.bind
  io.netty.channel.group.ChannelGroup.add
}
stop{
  io.netty.channel.group.ChannelGroup.close
  io.netty.channel.group.ChannelGroupFuture.awaitUninterruptibly
  io.netty.channel.socket.nio.NioServerSocketChannelFactory.releaseExternalResources
}
